An air-conditioning apparatus which executes a precooling operation or a preheating operation so that the indoor temperature reaches a target temperature at a designated time (a time set by the user) has conventionally been available. Regarding such an air-conditioning apparatus, an air-conditioning apparatus operation control method has been proposed in which a heat leakage coefficient and a temperature decrease coefficient are calculated in consideration of the condition in which the indoor temperature before a preheating operation has decreased, the amount of power consumption for setting the indoor temperature to a target temperature at a designated time is calculated and estimated on the basis of these coefficients, and operation is performed so that an air-conditioning apparatus is started when the amount of power consumption minimizes (see, for example, Patent Literature 1).